Display Backplane, Manufacturing Method Thereof, and Full-Screen Fingerprint Identification Display Device

ABSTRACT

The present disclosure provides a display backplane, a method for manufacturing the same and a full-screen fingerprint identification display device. The display backplane includes a substrate; a circuit layer disposed on a surface of the substrate; a light emitting device layer disposed on a surface of the circuit layer away from the substrate; and a plurality of fingerprint identification photodetectors disposed in at least one of the circuit layer and the light emitting device layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a U.S. National Phase Entry of InternationalApplication No. PCT/CN2020/085731 having an international filing date ofApr. 20, 2020, which is based on and claims priority to the ChinesePatent Application No. 201910514410.0, filed on Jun. 14, 2019. Theabove-identified applications are incorporated herein by reference intheir entireties.

TECHNICAL FIELD

The present disclosure relates to the field of display technology, andin particular, to a display backplane, a method for manufacturing thesame and a full-screen fingerprint identification display device.

BACKGROUND

In related technologies, collection of fingerprints is usuallyimplemented by a display device using the principle of pinhole imaging.However, this scheme needs the use of a high PPI (pixels per inch) imagesensor, has high cost and can only enable the display device toimplement fingerprint identification in local areas, but cannot enablethe display device to implement full-screen fingerprint identification,so the user experience is poor.

Therefore, the related technologies of the existing display devicesstill need to be improved.

SUMMARY

The present disclosure is intended to solve one of the technicalproblems in the related art at least to some extent. To this end, anobject of the present disclosure is to provide a display backplane whichhas simple structure and low cost, or can implement full-screenfingerprint identification.

In an aspect of the present disclosure, the present disclosure providesa display backplane. According to an embodiment of the presentdisclosure, the display backplane includes a substrate; a circuit layerdisposed on a surface of the substrate; a light emitting device layerdisposed on a surface of the circuit layer away from the substrate; anda plurality of fingerprint identification photodetectors disposed in atleast one of the circuit layer and the light emitting device layer. Thedisplay backplane has simple structure and low cost, since the pluralityof fingerprint identification photodetectors are disposed in the atleast one of the circuit layer and the light emitting device layer inthe display backplane and are located inside the display backplane, thedisplay backplane can implement full-screen fingerprint identification.

According to an embodiment of the present disclosure, there is a firstinsulating layer in the circuit layer, there is a second insulatinglayer in the light emitting device layer, and the fingerprintidentification photodetectors are embedded in at least one of the firstinsulating layer and the second insulating layer.

According to an embodiment of the present disclosure, the circuit layerincludes a thin film transistor disposed on the surface of thesubstrate; and a planarization layer disposed on a surface of the thinfilm transistor away from the substrate, the planarization layer formingthe first insulating layer, wherein the light emitting device layerincludes: a pixel defining layer disposed on the surface of the circuitlayer away from the substrate, the pixel defining layer defining aplurality of openings and forming the second insulating layer; and lightemitting elements disposed in the openings.

According to an embodiment of the present disclosure, the fingerprintidentification photodetector includes a first electrode and a secondelectrode, and the first electrode is electrically connected to a drainof the thin film transistor.

According to an embodiment of the present disclosure, the fingerprintidentification photodetector is embedded in the first insulating layer,and the second electrode is electrically connected to an anode in alight emitting element.

According to an embodiment of the present disclosure, photosensitivesurfaces of the fingerprint identification photodetectors aresubstantially parallel to the substrate.

According to an embodiment of the present disclosure, the fingerprintidentification photodetector is embedded in the second insulating layer,and the second electrode is electrically connected to a VDD signal lineof the circuit layer.

According to an embodiment of the present disclosure, the photosensitivesurfaces of the fingerprint identification photodetectors are arrangedobliquely relative to the substrate.

According to an embodiment of the present disclosure, included anglesbetween the photosensitive surfaces of the fingerprint identificationphotodetectors and the substrate are greater than or equal to 15° andless than or equal to 45°.

According to an embodiment of the present disclosure, the fingerprintidentification photodetectors are PIN photodiodes.

In an aspect of the present disclosure, the present disclosure providesa method for manufacturing the aforementioned display backplane.According to an embodiment of the present disclosure, the methodincludes forming a circuit layer on a surface of a substrate; forming alight emitting device layer on a surface of the circuit layer away fromthe substrate; and forming a plurality of fingerprint identificationphotodetectors in at least one of the circuit layer and the lightemitting device layer to obtain the display backplane. The method issimple and convenient to operate, easy to implement and easy to beindustrialized, and can effectively manufacture the aforementioneddisplay backplane, and the manufactured display backplane has simplestructure and lower cost, and can implement full-screen fingerprintidentification.

According to an embodiment of the present disclosure, the methodincludes forming a thin film transistor on the surface of the substrate;forming a plurality of fingerprint identification photodetectors on asurface of the thin film transistor away from the substrate; and forminga planarization layer on surfaces of the thin film transistor and thefingerprint identification photodetectors away from the substrate.

According to an embodiment of the present disclosure, the methodincludes: forming the plurality of fingerprint identificationphotodetectors on the surface of the circuit layer away from thesubstrate; forming pixel defining layers defining a plurality ofopenings on the surfaces of the fingerprint identificationphotodetectors; and forming light emitting elements in the openings.

In another aspect of the present disclosure, the present disclosureprovides a full-screen fingerprint identification display device.According to an embodiment of the present disclosure, the full-screendisplay device includes the display backplane described above. Thefull-screen fingerprint identification display device has simplestructure and low cost, and can implement full-screen fingerprintidentification, and has all features and advantages of theaforementioned display backplane, which will not be repeated herein.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a schematic cross-section view of a display backplaneaccording to an embodiment of the present disclosure.

FIG. 2 shows a schematic cross-section view of a display backplaneaccording to another embodiment of the present disclosure.

FIG. 3 shows a schematic cross-section view of a display backplaneaccording to still another embodiment of the present disclosure.

FIG. 4 shows a schematic cross-section view of a display backplaneaccording to still further embodiment of the present disclosure.

FIG. 5 shows a schematic cross-section view of a display backplaneaccording to still another embodiment of the present disclosure.

FIG. 6 shows a schematic cross-section view of a display backplaneaccording to still another embodiment of the present disclosure.

FIG. 7 shows a schematic cross-section view of a display backplaneaccording to still another embodiment of the present disclosure.

FIG. 8 shows a schematic plan view of a display backplane according toan embodiment of the present disclosure.

FIG. 9 shows a schematic cross-section view of the display backplaneaccording to the embodiment in FIG. 8 of the present disclosure.

FIG. 10 shows another cross-section view of the display backplaneaccording to the embodiment in FIG. 8 of the present disclosure.

FIG. 11 shows a circuit diagram of various components of the displaybackplane according to the embodiment in FIG. 8 of the presentdisclosure.

FIG. 12 shows a schematic flowchart of a method for manufacturing adisplay backplane according to an embodiment of the present disclosure.

FIGS. 13 a and 13 b show a schematic flowchart of a method formanufacturing a display backplane according to another embodiment of thepresent disclosure.

FIG. 14 shows a schematic flowchart of a method for manufacturing adisplay backplane according to still another embodiment of the presentdisclosure.

FIGS. 15 a, 15 b, 15 c, and 15 d show a schematic flowchart of a methodfor manufacturing a display backplane according to still anotherembodiment of the present disclosure.

FIG. 16 shows a flowchart of a method for manufacturing a displaybackplane according to still another embodiment of the presentdisclosure.

FIGS. 17 a, 17 b and 17 c show a flowchart of a method for manufacturinga display backplane according to still another embodiment of the presentdisclosure.

FIG. 18 shows a schematic cross-section view of a full-screenfingerprint identification display device according to an embodiment ofthe present disclosure.

FIG. 19 shows a schematic cross-section view of a full-screenfingerprint identification display device according to anotherembodiment of the present disclosure.

REFERENCE SIGNS

1: full-screen fingerprint identification display device; 10: displaybackplane; 11: touch screen outer frame area; 12: touch screen innerframe area; 13: inductive electrode; 14: driving electrode; 15: FPCbinding area; 16: FPC wiring area; 17: connection area; 18: connector;99: light; 100: substrate; 200: circuit layer; 210: first insulationlayer; 211: planarization layer; 220: thin film transistor; 221: source;222: drain; 223: gate; 224: active layer; 225: gate insulating layer;226: interlayer insulating layer; 227: gate scanning line; 228: readingline; 230: gate insulating layer; 240: interlayer insulating layer; 250:VDD signal line; 300: light emitting device layer; 310: secondinsulating layer; 311: pixel defining layer; 320: light emittingelement; 330: anode; 340: cathode; 400: fingerprint identificationphotodetector; 410: first electrode; 420: second electrode; 430:photosensitive surface; 500: packaging film; 600: color filter; 700:polarizer; 800: cover plate.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described in detail below. Theembodiments described below are exemplary and are intended to explainthe present disclosure, but should not be construed as limitation to thepresent disclosure. The embodiments in which specific technologies orconditions are not indicated shall be carried out according totechnologies or conditions described in literatures in the art oraccording to a product specification.

In an aspect of the present disclosure, the present disclosure providesa display backplane. According to an embodiment of the presentdisclosure, referring to FIGS. 1, 2 and 3 , the display backplane 10includes a substrate 100; a circuit layer 200 disposed on a surface ofthe substrate 100; a light emitting device layer 300 disposed on asurface of the circuit layer 200 away from the substrate 100; and aplurality of fingerprint identification photodetectors disposed in atleast one of the circuit layer 200 and the light emitting device layer300. The display backplane 10 has simple structure and low cost, and theplurality of fingerprint identification photodetectors 400 are disposedin the at least one of the circuit layer 200 and the light emittingdevice layer 300 in the display backplane 10 and are located inside thedisplay backplane 10 such that the display backplane 10 can implementfull-screen fingerprint identification.

According to an embodiment of the present disclosure, the substrate 100may include a base substrate, a buffer layer and a light-shieldinglayer. The specific positions and modes in which the base substrate,buffer layer and light-shielding layer are disposed are all the same asthe specific positions and modes in which the base substrate, bufferlayer and light-shielding layer are disposed in the conventional displaybackplane, and this will not be repeated herein.

According to an embodiment of the present disclosure, specifically, aslong as a plurality of fingerprint identification photodetectors 400 aredisposed in at least one of the circuit layer 200 and the light emittingdevice layer 300, their specific positions is not particularly limited.For example, in some embodiments of the present disclosure, theplurality of fingerprint identification photodetectors 400 may bedisposed in the circuit layer 200 (a schematic structure diagram refersto FIG. 1 ). In other embodiments of the present disclosure, theplurality of fingerprint identification photodetectors 400 may also bedisposed in the light emitting device layer 300 (a structure diagramrefers to FIG. 2 ). In yet other embodiments of the present disclosure,the plurality of fingerprint identification photodetectors 400 may alsobe disposed in the circuit layer 200 or the light emitting device layer300 (a structure diagram refers to FIG. 3 ). Therefore, the positionsand modes in which the fingerprint identification photodetectors 400 aredisposed are flexible, and they are simple in structure and low in cost,and suitable for industrialization.

According to an embodiment of the present disclosure, the circuit layer200 may include a thin film transistor, a gate insulating layer and aninterlayer insulating layer. The specific positions and modes in whichthe thin film transistor, the gate insulating layer and the interlayerinsulating layer are disposed are all the positions and modes in whichthe thin film transistor, the gate insulating layer and the interlayerinsulating layer are disposed in the conventional display backplane, andthis will not be repeated herein.

According to an embodiment of the present disclosure, the light-emittingdevice layer may include light emitting elements, cathodes and anodes.The specific positions and modes in which the light emitting elements,cathodes and anodes are disposed are all the positions and modes inwhich the light emitting elements, cathodes and anodes are disposed inthe conventional display backplane, and this will not be repeatedherein.

According to an embodiment of the present disclosure, the fingerprintidentification photodetectors may be embedded in the insulating layer.For example, in some embodiments of the present disclosure, referring toFIGS. 4 and 5 , there is a first insulating layer 210 in the circuitlayer 200, there is a second insulating layer 310 in the light emittingdevice layer 300, and the fingerprint identification photodetectors 400are embedded in at least one of the first insulating layer 210 and thesecond insulating layer 310. Therefore, the fingerprint identificationphotodetectors 400 are embedded in the insulating layer, are easy toform, and are simple in manufacturing process and low in cost. Moreover,when the fingerprint identification photodetectors are electricallyconnected, no short circuit will occur, and the display backplane 10 canbetter implement full-screen fingerprint identification.

According to an embodiment of the present disclosure, further, when thefingerprint identification photodetectors are embedded in the insulatinglayer, their specific positions are not particularly limited as long asthey are embedded in at least one of the first insulating layer 210 andthe second insulating layer 310. For example, in some embodiments of thepresent disclosure, the fingerprint identification photodetectors 400may be embedded in the first insulating layer 210 (a schematic structurediagram refers to FIG. 4 ); in other embodiments of the presentdisclosure, the fingerprint identification photodetectors 400 may alsobe embedded in the second insulating layer 310 (a schematic structurediagram refers to FIG. 5 ). Those skilled in the art can understand thatin yet other embodiments of the present disclosure, the fingerprintidentification photodetectors can also be embedded in the firstinsulating layer or the second insulating layer (not shown in thefigure). Therefore, the positions and modes in which the fingerprintidentification photodetectors 400 are disposed are flexible, and theyare simple in structure and low in cost, and suitable forindustrialization.

According to an embodiment of the present disclosure, specifically,referring to FIGS. 6 and 7 , the circuit layer includes a thin filmtransistor 220 disposed on a surface of the substrate 100; and aplanarization layer 211 disposed on a surface of the thin filmtransistor 220 away from the substrate 100, the planarization layer 211forming the first insulating layer. In addition, the light emittingdevice layer includes: a pixel defining layer 311 disposed on a surfaceof the circuit layer 200 away from the substrate 100, the pixel defininglayer 311 defining a plurality of openings and forming the secondinsulating layer; and light emitting elements 320 disposed in theopenings. Therefore, the fingerprint identification photodetectors 400are directly embedded in the planarization layer 211 (a schematicstructure diagram refers to FIG. 6 ) or the pixel defining layer 311 (aschematic structure diagram refers to FIG. 7 ) in the display backplane10, and they are simple in structure, low in cost, and easy toimplement, and can better implement full-screen fingerprintidentification.

According to an embodiment of the present disclosure, further, referringto FIGS. 8, 9, 10 and 11 , the display backplane includes a touch screenouter frame area 11, a touch screen inner frame area 12, an inductiveelectrode 13, a driving electrode 14, an FPC binding area (golden fingerarea) 15, an FPC wiring area 16, a connection area 17 and a connector 18(a schematic structure diagram refers to FIG. 8 ). The fingerprintidentification photodetector in the display backplane includes a firstelectrode 410 and a second electrode 420, and the first electrode 410 iselectrically connected to a drain 222 of the thin film transistor (aschematic structure diagram refers to FIGS. 9 and 10 ). Therefore, thefingerprint identification photodetectors can be driven by the thin filmtransistor without additional setting of driving for the fingerprintidentification photodetectors, so that the display backplane has simplestructure, is easy to be industrialized, and can better implementfull-screen fingerprint identification.

According to an embodiment of the present disclosure, further, when thefirst electrodes 410 are electrically connected to the drain 222 of thethin film transistor, the positions in which the fingerprintidentification photodetectors are disposed and their electricalconnection relationship are not particularly limited as long as thefingerprint identification photodetectors can operate. Specifically, insome embodiments of the present disclosure, the fingerprintidentification photodetectors can be embedded in the first insulatinglayer, that is, embedded in the aforementioned planarization layer 211,at this point, the second electrodes 420 of the fingerprintidentification photodetectors are electrically connected to anodes 330in the light emitting elements (a schematic structure diagram refers toFIG. 9 and a circuit diagram refers to FIG. 11 . It should be noted thatT₁ represents a thin film transistor and D₁ represents a light emittingelement in FIG. 11 ). In other embodiments of the present disclosure,the fingerprint identification photodetectors may be embedded in thesecond insulating layer, that is, embedded in the pixel defining layer311 described above. In this case, the second electrode 420 of thefingerprint identification photodetector is electrically connected tothe VDD signal line 250 of the circuit layer (a schematic structurediagram refers to FIG. 10 and a circuit diagram refers to FIG. 11 ).Therefore, the display backplane is simple in structure, low in cost,and easy to be industrialized, and can better implement full-screenfingerprint identification.

According to an embodiment of the present disclosure, as mentionedabove, when the light emitting elements emit light, positions of ridgesor valleys of fingers will be illuminated. The fingerprintidentification photodetectors are disposed in the display backplane, andcan receive different optical signals emitted from the ridges andvalleys of the fingers. Because refractive indices of valley and ridgeinterfaces are different, intensities of lights reflected to thefingerprint identification photodetectors are different, and then thefingerprint identification photodetectors convert optical signals withdifferent intensities into current signals with different intensities. Areading line 228 is controlled by the thin film transistor to read thecurrent signals with different intensities, so as to determine thedifference between different fingerprints, further implementingfull-screen fingerprint identification.

According to an embodiment of the present disclosure, when thefingerprint identification photodetectors are embedded in theaforementioned planarization layer 211, photosensitive surfaces 430 ofthe fingerprint identification photodetectors are substantially parallelto the substrate 100 (a schematic structure diagram refers to FIG. 9 ).Therefore, the display backplane is simple in structure on a whole, andthe fingerprint identification photodetectors in the planarization layerare simple in manufacturing process, low in cost, and easy to beindustrialized.

According to an embodiment of the present disclosure, when thefingerprint identification photodetectors are embedded in the pixeldefining layer 311, the photosensitive surfaces 430 of the fingerprintidentification photodetectors are arranged obliquely relative to thesubstrate 100 (a schematic structure diagram refers to FIG. 10 ).Therefore, since the photosensitive surfaces 430 of the fingerprintidentification photodetectors are arranged obliquely relative to thesubstrate 100, the amount of light absorption of the fingerprintidentification photodetectors can be increased compared with aconfiguration mode in which the photosensitive surfaces 430 aresubstantially parallel to the substrate 100, so that the intensity oflight received by the fingerprint identification photodetectors ishigher, which is beneficial to fingerprint identification.

According to an embodiment of the present disclosure, the inventor hasfound, after a profound study of the inclination degree of thephotosensitive surfaces 430 of the fingerprint identificationphotodetectors relative to the substrate 100, that when an includedangle θ between the photosensitive surfaces 430 of the fingerprintidentification photodetectors and the substrate 100 is greater than orequal to 15° and less than or equal to 45° (specifically, the includedangle θ may be 15°, 20°, 25°, 30°, 35 , 40° or 45°, etc.), light rayscan be incident substantially perpendicular to the photosensitivesurface 430, so that the amount of light absorption of the fingerprintidentification photodetectors can be further increased, thereby furtherimproving the intensity of light received by the fingerprintidentification photodetectors, and further facilitating fingerprintidentification.

In some specific embodiments of the present disclosure, the fingerprintidentification photodetectors may be PIN photodiodes. Therefore, thefingerprint identification photodetectors have small junctioncapacitance, short transit time, high sensitivity, low cost and simplestructure, are easy to be industrialized, and can better implementfull-screen fingerprint identification.

In one aspect of the present disclosure, the present disclosure providesa method for manufacturing the aforementioned display backplane.According to an embodiment of the present disclosure, referring to FIGS.12, 13 a and 13 b, 1, 2 and 3, the method includes the following steps.

In S100, a circuit layer 200 is formed on a surface of a substrate 100(a schematic structure diagram refers to FIG. 13 a ).

According to an embodiment of the present disclosure, the step offorming the circuit layer 200 may include forming a buffer layer on thebase substrate, and then forming an active layer on a surface of thebuffer layer, the specific processes may be conventional processes offorming the buffer layer and forming the active layer. Specifically, theactive layer may be formed after exposure, etching and development.Therefore, the operation is simple, convenient, easy to implement andeasy to be industrialized.

According to an embodiment of the present disclosure, the step offorming the circuit layer 200 further includes the step of performingN-type or P-type doping on a source region and a drain region on theactive layer mentioned above, so as to form a source contact region anda drain contact region on the surface of the active layer, the specificprocess may be a conventional doping process, and will not be repeatedherein. Therefore, the operation is simple, convenient, easy toimplement and easy to be industrialized.

According to an embodiment of the present disclosure, the step offorming the circuit layer 200 further includes steps of forming a gateinsulating layer on a surface of the active layer and forming a gate ona surface of the gate insulating layer away from the active layer, thespecific processes may be conventional processes, and will not berepeated herein. Therefore, the operation is simple, convenient, easy toimplement and easy to be industrialized.

According to an embodiment of the present disclosure, the step offorming the circuit layer 200 further includes steps of forming aninterlayer insulating layer and forming an interlayer insulating layervia hole in contact with the aforementioned source region and the drainregion through exposure, etching and development processes, the specificprocesses may be conventional processes. A structure of the formed viahole is the same as that in the conventional interlayer insulatinglayer, and will not repeated herein. Therefore, the operation is simple,convenient, easy to implement and easy to be industrialized.

According to an embodiment of the present disclosure, the step offorming the circuit layer 200 further includes a step of forming asource and a drain and a step of forming a reading line in a displaybackplane, the specific processes may be conventional processes, andwill not be repeated herein. Therefore, the operation is simple,convenient, easy to implement and easy to be industrialized.

According to an embodiment of the present disclosure, the step offorming the circuit layer further includes a step of forming aplanarization layer, the process may be a conventional process, and willnot be repeated herein. Therefore, the operation is simple, convenient,easy to implement and easy to be industrialized.

In S200, a light emitting device layer 300 is formed on the surface ofthe circuit layer 200 away from the substrate 100 (a schematic structurediagram refers to FIG. 13 b ).

According to the embodiment of the present disclosure, the step offorming the light-emitting device layer 300 may include steps of forminganodes, pixel defining layers, light emitting elements, cathodes, apackaging film, the specific processes may be conventional processes,and will not be repeated herein. Therefore, the operation is simple,convenient, easy to implement and easy to be industrialized.

In S300, a plurality of fingerprint identification photodetectors 400are formed in at least one of the circuit layer 200 and the lightemitting device layer 300, so as to obtain the display backplane 10 (aschematic structure diagram refers to FIGS. 1, 2 and 3 ).

Specifically, in some embodiments of the present disclosure, theplurality of fingerprint identification photodetectors may be formed inthe planarization layer of the circuit layer (a schematic structurediagram of the manufactured display backplane refers to FIG. 9 ). Inother embodiments of the present disclosure, the plurality offingerprint identification photodetectors may also be formed in thepixel defining layer of the light emitting device layer (a schematicstructure diagram of the manufactured display backplane refers to FIG.10 ). Therefore, the aforementioned display backplane can be effectivelymanufactured, and specific features and advantages of the displaybackplane are the same as those described above, and will not berepeated herein.

In a specific embodiment of the present disclosure, when the pluralityof fingerprint identification photodetectors are formed in theplanarization layer of the circuit layer 200, referring to FIG. 14 andFIGS. 15 a to 15 d , the method may include the following steps.

In S100′, a thin film transistor 220 is formed on the surface of thesubstrate 100 (a schematic structure diagram refers to FIG. 15 a ).

In S200′, the plurality of fingerprint identification photodetectors 400are formed on a surface of the thin film transistor 220 away from thesubstrate 100 (a schematic structure diagram refers to FIG. 15 b ).

In S300′, a planarization layer 211 is formed on surfaces of the thinfilm transistor 220 and the fingerprint identification photodetectors400 away from the substrate 100 (a schematic structure diagram refers toFIG. 15 c ).

According to an embodiment of the present disclosure, after theplanarization layer 211 is formed, steps of forming the pixel defininglayer 311 and forming light emitting elements 320 may be furtherincluded. A schematic structure diagram of the manufactured displaybackplane refers to FIG. 15 d , and the processes of the previous stepsmay be conventional processes, and will not be repeated herein.

In another specific embodiment of the present disclosure, when theplurality of fingerprint identification photodetectors are formed in thepixel defining layer of the light emitting device layer, referring toFIG. 16 and FIGS. 17 a to 17 c , the method may include the followingsteps.

In S100″, the plurality of fingerprint identification photodetectors 400are formed on the surface of the circuit layer (including the thin filmtransistor 220 and the planarization layer 211) away from the substrate100 (a schematic structure diagram refers to FIG. 17 a ).

According to an embodiment of the present disclosure, both the step andprocess of forming the circuit layer including the thin film transistor220 and the planarization layer 211 on the substrate are the same asthose described above, and will not be repeated herein.

In S200″, the pixel defining layers 311 defining a plurality of openingsare formed on surfaces of the fingerprint identification photodetectors400 (a schematic structure diagram refers to FIG. 17 b ).

In S300″, light emitting elements 320 are formed in the openings (aschematic structure diagram refers to FIG. 17 c ).

According to embodiments of the present disclosure, the processes of theabove steps can all be conventional processes, and will not be repeatedherein.

In another aspect of the present disclosure, the present disclosureprovides a full-screen fingerprint identification display device.According to an embodiment of the present disclosure, referring to FIGS.18 and 19 , the full-screen display device 1 includes the aforementioneddisplay backplane. As described above, when the light emitting elementsemit light 99, positions of ridges or valleys of fingers will beilluminated. The fingerprint identification photodetectors are disposedin the full-screen fingerprint identification display device, and canreceive different optical signals emitted from the ridges and valleys ofthe fingers. Because refractive indices of valley and ridge interfacesare different, intensities of lights reflected to the fingerprintidentification photodetectors are different, and then the fingerprintidentification photodetectors convert optical signals with differentintensities into current signals with different intensities. A readingline is controlled by the thin film transistor to read the currentsignals with different intensities, so as to determine the differencebetween different fingerprints, further implementing full-screenfingerprint identification. Moreover, the full-screen fingerprintidentification display device 1 has simple structure and low cost, andhas all the features and advantages of the display backplane describedabove, which will not repeated herein.

According to embodiments of the present disclosure, it can be understoodby those skilled in the art that in addition to the structure describedabove, the full-screen fingerprint identification display device furtherincludes the structure and components of a conventional display device,which will not be repeated herein.

According to embodiments of the present disclosure, the type of thefull-screen fingerprint identification display device is notparticularly limited, and can specifically include, but is not limitedto, mobile phones, game machines, readers, tablet computers, and thelike.

In addition, the terms “first” and “second” are used for the purpose ofdescription only, and cannot be understood as indication or implicationof relative importance or implicit indication of the number of thementioned technical features. Thus, features defined by “first” and“second” may include one or more of the features explicitly orimplicitly. In the description of the present disclosure, the meaning of“a plurality of” is two or more than two, unless defined otherwiseexplicitly.

In the present disclosure, unless otherwise clearly specified anddefined, the first feature being “on” or “under” the second feature maymean that the first and second features are in direct contact, or thefirst and second features are in indirect contact through anintermediary. Moreover, the first feature being “over”, “above” and “on”the second feature may mean that the first feature is directly above orobliquely above the second feature, or simply mean that a height of thefirst feature from a horizon is greater than that of the second feature.The first feature being “below”, “beneath” and “under” the secondfeature may mean that the first feature is directly below or obliquelybelow the second feature, or simply mean that a height of the firstfeature from a horizon is less than that of the second feature.

In the description of the specification, description made with referenceto terms “an embodiment”, “some embodiments”, “an example”, “a specificexample” or “some examples” means that a specific feature, structure,material, or characteristic described in connection with the embodimentor example is included in at least one embodiment or example of thepresent disclosure. In this specification, the schematic expression ofthe above-mentioned terms is not necessarily directed to the sameembodiment or example. Moreover, the specific feature, structure,material, or characteristic described may be combined in a proper way inany one or more embodiments or examples. In addition, those skilled inthe art may incorporate and combine different embodiments or examplesand features of the different embodiments or examples described in thisspecification without conflict.

Although the embodiments of the present disclosure have been shown anddescribed above, it should be understood that the above embodiments areexemplary, and will not be understood as the limitation to the presentdisclosure. Alterations, modifications, substitutions and variations tothe above embodiments may be made by those skilled in the art within thescope of the present disclosure.

What we claim is:
 1. A display backplane, comprising: a substrate; acircuit layer disposed on a surface of the substrate; a light emittingdevice layer disposed on a surface of the circuit layer away from thesubstrate; and a plurality of fingerprint identification photodetectorsdisposed in at least one of the circuit layer and the light emittingdevice layer.
 2. The display backplane according to claim 1, wherein thecircuit layer contains a first insulating layer, the light emittingdevice layer contains a second insulating layer in, and the fingerprintidentification photodetectors are embedded in at least one of the firstinsulating layer and the second insulating layer.
 3. The displaybackplane according to claim 1 or 2, wherein the circuit layercomprises: a thin film transistor disposed on the surface of thesubstrate; and a planarization layer disposed on a surface of the thinfilm transistor away from the substrate, the planarization layer formingthe first insulating layer, wherein the light emitting device layercomprises: a pixel defining layer disposed on the surface of the circuitlayer away from the substrate, the pixel defining layer defining aplurality of openings and forming the second insulating layer; and lightemitting elements disposed in the openings.
 4. The display backplaneaccording to claim 2, wherein each of the fingerprint identificationphotodetectors comprises a first electrode and a second electrode, thefirst electrode is electrically connected to a drain of the thin filmtransistor.
 5. The display backplane according to claim 4, wherein eachof the fingerprint identification photodetectors is embedded in thefirst insulating layer, and the second electrode is electricallyconnected to an anode in one of the light emitting elements.
 6. Thedisplay backplane according to claim 1, wherein photosensitive surfacesof the fingerprint identification photodetectors are substantiallyparallel to the substrate.
 7. The display backplane according to claim4, wherein the fingerprint identification photodetector is embedded inthe second insulating layer, and the second electrode is electricallyconnected to a VDD signal line of the circuit layer.
 8. The displaybackplane according to claim 1, wherein the photosensitive surfaces ofthe fingerprint identification photodetectors are arranged obliquelyrelative to the substrate.
 9. The display backplane according to claim1, wherein included angles between the photosensitive surfaces of thefingerprint identification photodetectors and the substrate are greaterthan or equal to 15° and less than or equal to 45°.
 10. The displaybackplane according to claim 1, wherein the fingerprint identificationphotodetectors are PIN photodiodes.
 11. A method for manufacturing thedisplay backplane according to claim 1, comprising: forming a circuitlayer on a surface of a substrate; forming a light emitting device layeron a surface of the circuit layer away from the substrate; and forming aplurality of fingerprint identification photodetectors in at least oneof the circuit layer and the light emitting device layer, to obtain thedisplay backplane.
 12. The method according to claim 11, comprising:forming a thin film transistor on the surface of the substrate; formingthe plurality of fingerprint identification photodetectors on a surfaceof the thin film transistor away from the substrate; and forming aplanarization layer on surfaces of the thin film transistor and thefingerprint identification photodetectors away from the substrate. 13.The method according to claim 11, comprising: forming the plurality offingerprint identification photodetectors on the surface of the circuitlayer away from the substrate; forming a pixel defining layer defining aplurality of openings on the surfaces of the fingerprint identificationphotodetectors; and forming light emitting elements in the openings. 14.A full-screen fingerprint identification display device comprising thedisplay backplane according to claim
 1. 15. The display backplaneaccording to claim 2, wherein the circuit layer comprises: a thin filmtransistor disposed on the surface of the substrate; and a planarizationlayer disposed on a surface of the thin film transistor away from thesubstrate, the planarization layer forming the first insulating layer,wherein the light emitting device layer comprises: a pixel defininglayer disposed on the surface of the circuit layer away from thesubstrate, the pixel defining layer defining a plurality of openings andforming the second insulating layer; and light emitting elementsdisposed in the openings.
 16. The display backplane according to claim3, wherein each of the fingerprint identification photodetectorscomprises a first electrode and a second electrode, the first electrodeis electrically connected to a drain of the thin film transistor. 17.The display backplane according to claim 2, wherein photosensitivesurfaces of the fingerprint identification photodetectors aresubstantially parallel to the substrate.
 18. The display backplaneaccording to claim 3, wherein photosensitive surfaces of the fingerprintidentification photodetectors are substantially parallel to thesubstrate.
 19. The display backplane according to claim 4, whereinphotosensitive surfaces of the fingerprint identification photodetectorsare substantially parallel to the substrate.
 20. The display backplaneaccording to claim 5, wherein photosensitive surfaces of the fingerprintidentification photodetectors are substantially parallel to thesubstrate.